Manufacture of medicinal oils and other viscous decolorized products of petroleum



E. B. CUBB. MANUFACTURE 0F MEDICINAL OILS AND OTHER VISCOUS DECOLOHIZED PRODUCTS 0F PETROLEUM.

APPLICATION FILED JUNE I. mr.

Semp@ on @t n. Q k` s o N @wma E. B. COBB.

MANUFACTURE 0F MEDICINAL OILS AND OTHER VISCDUS DECOLORIZED PRODUCTS OF PETROLEUM.

APPLICATION FILED JUNE Tx 191?.

Patented Aug. 23, 1921. b 2 SHEETS-SHEET 2.

Alli LA.

UNlTEosTATEs PATENT OFFICE.

ERNEST B. CORD, OF JERSEY CITY, NEW JERSEY, ASSIGNOR PANY, OF BAYONNE, NEW JERSEY, A CORPORATION TO STANDARD OIL COM- OF NEW JERSEY.

MANUFACTURE OF MEDICINAL OILS AND OTHER VISCOUS DECOLORIZED PRODUCTS OF PETROLEUM.

Specification of Letters Patent.

Patented Aug. 23, 1921.

Application led .Tune 7i', 1917. Serial No. 173,312.

T0 all whom it may concern.'

Be it known that I, ERNEST B. Conn, a citizen of the United States, residing at Jersey Cit in the county of Hudson and State of l ew Jersey, have invented certain new and useful Improvements in the Manufacture of Medicinal Oils and other Viscous Decolorized Products of Petroleum, of which the following is a specification.

This invention relates more particularly to the manufacture of medicinal oils from -petroleum; but each improvement is intended to be secured for all appropriate uses.

Figures l and 2 of the accompanying drawings are diagrams of apparatus appropriate for use in obtaining the components of a special stock useful for the preparation of medicinal oil therefrom and hereinafter more particularly described; While Figs. 8 and 4 taken together constitute a diagram of apparatus appropriate for use in operating upon the same or upon other sultable stock.

The viscosities mentioned herein are those which would be indicated by a Saybolt universal viscosimeter, through Which an equal volume of Water would pass in thirty-one seconds at 60O F.

A procedure which embodies the several improvements composing the invention is as follows:

First. Two or more distillates, Whose constituent hydrocarbons have viscosities above forty seconds at 100 F. and are in lar e part of equal gravities in the different d1stillates, are obtained from petroleum of such different types that the constituent hydrocarbons are of different viscosities for equal gravities in the different distillates; and the manner of obtaining said distillates is such that these differ (as a Whole) from each other in viscosity and that the hydrocarbons of smaller viscosities for e ual gravities occur in a more viscous distil ate (or distillates). Thus, for example, the hydrocarbons in petroleum of the Texas type are less viscous than' those of e ual gravities in petroleum of the Illinoisansias-Oklahoma type; and a more viscous distillate of the Texas type and a less viscous distillate of the Illinois-Kansas-Oklahoma type are suitable for a binary stock.

Second. Assuming that one or more of the stock distillates are not suiiciently free from congealable substance, the same are chilled to a suitably low temperature and then passed through a Filter press; and such chilling and pressing are repeated, if necessary or expedient. An Illinois-Kansas- Oklahoma distillate for example, has naturally a content of paraffin Wax. A distillate of the Texas type contains no paraflin wax naturally.

Third. The stock distillates, Without treatment other than the removal of congealable substance as aforesaid, are mixed 1n such proportions that the distillate (or distillates) of greater viscosity than the remainder of the stock constitutes about fifty per cent. by volume of the mixture as a minimum, say between about fifty per cent. and about ninety-live per cent. of the same. Moreover, it is designed Vfor the so-compounded stock to have a viscosity of more than about eighty seconds at 100o F., the particular viscoslty above eight seconds in each case to be according to t e preference of the manufacturer, Within the limits of practicability, and the stock distillates to have correspondin viscosities.

The preparation o a stock of about 425 seconds at 100 F. by mixing certain distillates of the Texas type and the Illinois- Kansas-Oklahoma type respectively is specifically described hereinafter by Way of example.

Fourth. The stock is treated with sulfuric acid of about 1.835 specific gravity (containing about 92H70 to 93% by Weight of sulfuric monohydrate, H2SO4); and the acid sludge is separated from the treated oil.

Fifth. The thus treated oil is subjected to so energetic a treatment with fuming sulfuric acid that a suitably cleared sample of the acid treated oil, when tested with hot sulfuric acid in the manner prescribed by the British Pkarmaoopz'a for paraiinum liquidum, will color the originally colorless4 testing acid not darker than apale shade of brown; which coloration (for the purposes of the present specification) may be taken to be not darker than that possessed by a freshly prepared of potassium iodid and two-tenths of a gram of iodin (the solid substance) in one liter of distilled water. Chemically pure sulfuricacid of about 1.835 specific gravity is suitable for the testing acid.

The prescription of the British Pharm-acopz'a referred to is that three cubic centimeters of the oil are to be heated with an equal volume of sulfuric acid in a testtube placed in boiling water for 10 minutes, with frequent agitation (U. S. Dispeusmtory, edition of 1907, under Petrolatum liquidum).

A suitable mode of clearing a sample of the acid treated oil for this test consists in settling and drawing off the acid sludge, taking a suitable quantity (say one barrel) of the remaining oil, neutralizing the acidity of the oil thus taken out with caustic soda lye, say about 1.075 specific gravity', settling and drawing off the alkaline sludge, distilling the neutralized oil with injection of dry steam into the oil operated upon, treating the so obtained distillate with five per cent. by volume of fuming sulfuric acid (consisting of 20% by weight of sulfuric anhydrid and 80% of sulfuric. monohydrate), settling and drawing olf the resulting acid sludge, blowing the remaining oil with air while in its acid condition until free from sulfur dioxid, and filtering a sample of the blown oil four hundred cubic centimeters in volume through two hundred grams of freshly calcined Florida clay in a glass tube one and a half inches in diameter.

If after treating a given stock with the amount of fuming sulfuric acid which may be estimated as suflicient, a sample of the acid treated oil should be cleared and tested with hot sulfuric acid, all as just described, the color of the testing acid (at the close of the test) will of course either be darker, or else not darker, than a pale shade of brown as defined. lf darker, the oil from which the sample was taken would be further treated with fuming sulfuric acid in appropriate proportion; until a cleared sample of the acid treated oil should no longer color the testing acid darker than a pale shade of brown as defined. And even if the color of the testing acid at the close of the test should not be darker than a pale shade of brown, as defined, the coloration of it may be darker than is considered desirable by the manufacturer; and in that case it would be most advantageous to subject the oil from which the sample was taken to further treatment with fuming sulfuric solution of one gram4 acid in appropriate proportion, until thetesting acid applied to a cleared sample is (after testing) of the desired and obtainable light color.

Sixth. The main body of acid treated oil and the acid sludge are separated from each other.

Seventh. The acidity of the oil is neutralized with alkaline material; and part at least of the spent alkali (say as much as can conveniently be separated) is then removed from the neutralized oil.

Eighth. The neutralized oil is distilled with special agency for avoidance of cracking; and the useful distillate is collected apart from such runnings, if any, as may be considered unsuitable for further operating upon as hereinafter set forth.

Ninth. The useful distillate is heated around 400 F. to 500O F. in order to desulfurize the same; and this desulfuration is considered complete when a strip of copper can remain in a sample of oil for say two hours at 212c F. without tarnishing.

Tenth. Concurrently with a part at least of the said desulfuration, dry steam is injected into the oil until the flash point and the viscosity of the oil have been raised to a substantial extent,` to wit, to such extent as is exemplified hereinafter, or to such other extent as the operator may determine.

Eleventh. The oil is next treated with a comparatively small proportion of fuming sulfuric acid. in order to remove the still odor and also to free the oil from readily carbonizable substances which may have been developed in the special distillation aforesaid, following the earlier treatment with fuming sulfuric acid.

Twelfth. The acid treated oil and the acid sludge are separated from each other.

Thirteenth. The so separated oil is blown in its acid condition with air injected into the oil until the latter is free from sulfur dioxid.

Fourteenth. The blown oil is filtered in its acid condition through Florida clay, fullers earth.

Fifteenth. The filtrate is (ordinarily at least) the finished product; but if further treatment should be desired, on account of a suggestion of odor or taste therein, or for any other reason, the said filtrate can be acted on by steam injected into the oil at about 212 F. Volatile impurities, if any, therein would pass off with the uncondensed steam; and the water soluble impurities, if any, would be washed out by the hot water of condensation.

Sixteenth. The washed filtrate is filtered again through Florida clay (fullers earth) for brightenmg the appearance of the oil, if for no other purpose.

The said procedure can be modified by addition, omission, substitution or otherwise as long as the substance is retained of any one or more of the claims at the close of this specification.

Thus, for example, with respect to the stock to be operated upon, (first) the said stock need not be subjected to chilling and pressing` for removal of congealable substance, if the finished product therefrom should be acceptable for its intended use; (second) the mixing of the component distillates to form the aforesaid compound stock could, if preferred, be performed after treating one or more of said component distillates with sulfuric acid or otherwise advancing the same toward the condition of decolorized oil; (third) if the advantages are waived of a stock specially ,compounded as aforesaid the stock may be obtained in any other suitable way; and (fourth) while the Stock should consist of hydrocarbons with viscosities above forty seconds at 100O F., it need not have a viscosity above eighty seconds at 100o F. as aforesaid if the desired product should be derivable from stock of less viscosity.

In these modifications (first to fourth) stock which consists of' one or more petroleum distillates would best be operated upon as hereinabove set forth for the aforesaid specially compounded stock. If it should be desired to obtain such products as may be derivable from oils of non-petroleum origin, but more or less closely analogous to petroleum, such as shale oils, for example, viscous oil of this description can be operated upon in accordance with an appro priate part at least of the foregoing procedure. The use of vaseline and other hydrocarbon substances not liquid at 60o F., as stock (say for the manufacture of finished products of corresponding consistency) is not necessarily excluded.

lVith respect to operations to be performed on the stock prior to the aforesaid special distillation, (fifth) the treatment which employs sulfuric acid of about 1.835 specific gravity can be omitted with only the loss which results from having to use somewhat more or the stronger sulfuric acid which is subsequently to be em loyed in the foregoing procedure; (sixth for the manufacture of a product which does not have to stand the aforesaid hot acid test (coloration of the acid not darker than pale brown, as well as for a product which is to stand the same, it is advantageous to treat the stock with sulfuric acid in so energetic a manner that a suitably cleared sample of the acid treated oil will exhibit at least approximately as great a freedom from readily carbonizable substances as may be desired in the finished product; (seventh) it is possible (although not so advantageous) before the special distillation to use a less energetic treatment with sulfuric acid than this, whether the finished product is lor is not required to stand said hot acid test; but the distillate from said special distillation would then be subjected to a more energetic treatment with sulfuric acid than is called for by the foregoing procedure; (eighth) lother forms of sulfuric acid stronger than that of about 1.835 specific gravity, such as sulfuric anhydrid and nonf'uming acid containing more than about 93% of sulfuric monohydrate (H2804) can be applied to the stock instead of or in addition to fuming sulfuric acid as aforesaid, provided the treatment employing the same shall be effective for obtaining an acceptable product; and (ninth) while one very important effect of the aforesaid special distillation is the separation of the sulfonic bodies from the acid treated oil (which latter distils over), it is permissible (if so preferred) to subject the acid treated stock (after separation of' the acid sludge and prior to said special distillation) to a washing with methyl alcohol or ethyl alcohol` or to any other known or suitable means of Separating sulfonic bodies from oil without distillation. Vashing with water, or with alkaline lyes of the strengths customarily used in treating lubricating oils, would be little (if at all) suitable for separating sulfonic bodies from viscous oils which have been energetically treated with sulfuric acid as aforesaid, in view of the liability of these oils when so treated to form intractable emulsions with water, or with said alkaline 1 es.

yIn these modifications (fifth to ninth) the stock is treated in every case (as also in the foregoing procedure) with sulfuric acid stronger than that of about 1.835 specific gravity; and the acid treated stock would best be subjected in every case to the aforesaid special distillation; the resulting distillate to be best operated upon as set forth for the corresponding distillate in the foregoing procedure; except that (as already mentioned) a more energetic treatment of the said distillate would be needed in modification (seventh). In the modification (seventh) the amount of fuming acid in the treatments which respectively precede and follow the special distillation might constitute, for example, the same percentage of the oil to be treated therewith; but other proportions can be used instead, if preferred.

With respect to the series of operations which in the fore oing procedure begins with the special distillation and ends with a sullOt furic acid treatement just before filtration, (tenth) the acid treated stock, from which the sulfonic bodies have been separated by the aforesaid special distillation or by other means in connection with the special distillation as aforesaid, need not be desulfurized by heating the same to around 400 to 500o F., if an acceptable product should be obtainable without such desulfuration; (eleventh) by an appropriately regulated injection of steam at a temperature below that at which the bulk at least of the oil will distil off' the flash oint of the oil can be raised substantially without necessarily increasing the viscosit of the oil to a substantial extent; (twel th) the raising of the flash point of the oil can be omitted when not requlred; (thirteenth) where there is both a desulfuration by heating around 400 F. to 500o F. and a raising of the flash point (or the flash point and viscosity) by injection of steam, these operations can be applied in succession; and the order of their application can be varied; but it is more advantageous for part at least of the said injection of steam to be performed concurrently with or after the desulfurizing operation rather than the whole of it before the latter; because the steam will expel any traces of hydrogen sulfid remaining in the oil; (fourteenth) in treating distillate from the aforesaid special distillation with sulfuric acid use can be made of sulfuric acid of about 1.835 specific gravity in addition to the stronger acid (or instead of the latter where said acid of about 1.835 specific gravity will answer), and any other appropriate form of stronger sulfuric acid can be used instead of or in addition to furning sufuric acid; (fifteenth) the blowing of the acid treated distillate in its acid condition with air for removal of sulfur dioxid can be omitted when not required; (sixteenth) after treating the distillate from the aforesaid special distillation with sulfuric acid and before filtering the acid treated distillate, it may be preferred to wash the sulfonic bodies out of the oil, using Say meth l alcohol or ethyl alcohol; and (seventeent the sulfuric acid treatment of the distillate from the aforesaid special distillation might be omitted in case a roduct acceptable for its intended use should) be obtainable without it.

In these modifications (tenth to seventeenth) the acid treated stock from which the sulfonic bodies have been separated would best be filtered through freshly calcined Florida clay (fullers earth), after having been subjected (so far as may be necessary or expedient) to the operations which in the foregoing procedure are applied before filtration toV` the distillate from the aforesaid special distillation; except, of course, that the procedure messes would be changed in the particulars which are characteristic of the several modifications. The filtration would be performed in acid or in non-acid condition, as required by the particular modification, or as preferred, should the modification admit of such preference.

With respect to filtration, reference has been made already to the permissible performance of that operation 1n non-acid condition, instead of in acid condition, according to its appropriateness and to preference. Also it is to be observed in respect thereto (eighteenth) that if preferred, the oil can be filtered through other solid decolorizing material, instead of or in addition to Florida clay (fullers earth); (nineteenth) that where there is more than one filtration the filtering material need not be always the same2 but may be different in the different filtering operations; and (twentieth) that filtration might be omitted where a product acceptable for its intended use is obtainable without it.

)Vith respect to the further treatment (when desired) of the filtered oil, which ordinarily would be a finished product, the same (twenty-first) can be acted upon with sulfuric acid instead of being subjected to the aforesaid steaming at about 212 F.; and the acid treated oil would best be filtered through Florida clay (fullers earth).

In the foregoing procedure, therefore, and in each of the above described modifications thereof, oil composed of hydrocarbons with viscosities above forty seconds at 100O F. is decolorized by a process which includes a treatment with sulfuric acid stronger than that of about 1.835 specific gravity, and a subsequent separation of sulfonic bodies, along with such other operations as may be appropriate in the particular case; but, inasmuch as the aforesaid specially compounded stock is new in itself and has never been subjected to any process of decolorizing, the said stock can (twenty-second) be subjected to any known or suitable decolorizing operations (without exceeding the soope of the invention) as well as to those herein above set forth.

The decolorizing intended here, and elsewhere in this specification, is primarily one by which the oil is so far freed from coloring matter as to be at least approximately Water white; but oil which is rendered notably lighter in color without being approximately water white would also be decolorized vvithin the intended meaning of the Word.

The reference to particular modifications is not intended to exclude others. Steam and air are both forms of aeriform fluid, and may be substituted one for the other (or be used together) when appropriate. Moreover, other aeriform uid can be used, if desired.

The use (medicinal or other) to which the linished oil is to be (or may actually be) put is no part of the invention.

Referring to the accompanying drawings, the still a of Fig. 1 has, as shown, an oil supply pipe b, a vapor outlet pipe c, a steam inlet ipe f with distributer g and a drawoff /L or residual material. The letter o indicates a valve wherever it occurs in any figure. The condensing coil d of Fig. 1 is immersed in cooling Water in container e. It receives vapors from still a through pipe c and delivers distillate through pipe lo to receiver Z or through j elsewhere, according to the adjustment of the valves. Uncondensed vapors pass ofi' by the pipe i. The draw-oil` Z is for the water formed by condensation of the steam injected into still a.

The still p of Fig. 1 is supplied by pump m with distillate from receiver Z through pipe n. It has, as shown, a vapor outlet pipe g (which leads to a condenser, not shown), a steam inlet pipe t with distributer u, and a draw-olf pipe r. This latter is immersed in cooling Water in container s and leads to a storage tank, not shown.

The still 12 of Fig. 2, as show-n, has an oil supply pipe 13, a vapor outlet pipe 14 and a draw-oit 17. The condensingr coil 15 is immersed in cooling water in container 16. It receives vapors from still 12 and delivers distillate through pipe 20 to receiver 21, or through pipe 19 elsewhere, according to the adjustment of the valves. Uncondensed vapors pass o' by pipe 18.

The chilling appliance 24 is supplied with distillate ,from receiver 21 by pump 22 through pipe 23. It delivers the chilled oil through ipe 25 to filter press 26.

The agitator 28 of Fig. 2 is supplied with pressed distillate through pipe 27 and with sulfuric acid through pipe 29. It has, as shown, an air injection pipe 30, a draw-off 31 for acid sludge, and a draw-off 32 for the acid treated oil.

The agitator 35 of Fig. 2 is supplied with oil from agitator 28 by pump 33 through pipe 34 and with alkaline lye through pipe 36. It has, as shown, an air injection pipe 37, a draw-olf 38 for the spent alkali (alkaline sludge), and a draw-off 39 for the oil. This latter draw-off leads to storage tank 40.

The still 43 of Fig. 2 is supplied by pump 41 through pipe 42 with oil from tank 40. It has, as shown, a vapor outlet pipe 44, a steam inlet pipe 47 with distributer 48, and a drawo' 45. The vapor pipel 44 leads to a condenser, not shown. The draw-off pipe 45 is immersed in cooling water in container 46 and leads to a storage tank, not shown.

The agitator 50 of Fig. 3, as shown, has an oil supply pipe 51, an acid supply pipe 52, an air injection pipe 53, a draw-off 54 for acid sludge, and a draw-oftI 55 for the acid treated oil.

The agitator 58 of Fig. 3 is supplied with acid treated oil from agitator 50 by pump 56 through pipe 57 and with alkaline lye through pipe 59. It has, as shown, an air injection pipe 60, a draw-off 61 for the spent alkali (alkaline sludge) and a draw-olii' 62 for the oil. This latter draw-oli' 62 leads to storage tank 63.

The still 66 of Fig. 3 is supplied with oil from tank 63 by pump 64 through pipe 65. It has, as shown, a vapor outlet pipe 67, a steam inlet pipe 70 with distributer 71, and a draw-off 72. The condensing coil 68 is immersed in cooling water in container 69. It receives vapors from still 66 and delivers distillate through pipe 74 to' receiver 75. Uncondensed vapors pass off by pipe 73. The draw-oit 750 is for the water formed by condensation of the steam injected into still 66.

The still 78 of Fig. 3 is supplied with distillate from receiver 75 by pump 76 through pipe 77. It has, as shown, a vapor outlet pipe 79 leading to a condenser, not shown, a steam inlet pipe 83 with distributer 84, and a draw-oli' 80; which latter is immersed in cooling Water in container 81 and leads to storage tank 82 in Fig. 4.

The agitator 85 of Fig. 4 is supplied with oil from tank 82 by pump 86 through pipe 87 and with sulfuric acid through pipe 88. It has, as shown, an air injection pipe 89, a draw-ofi' 90 for the acid sludge, and a drawof 91 for the acid treated oil. This latter draw-off 91 leads to storage tank 92.

The filters 95 of Fig. 4 are supplied with oil from tank r92 by pump 93 through pipe 94. The filtrate passes by pipe 96 into the storage tank 97.

The agitator 100 of Fig. 4 is supplied with filtered oil from tank 97 by pump 98 through pipe 99 and with steam through pipe 105. It has, as shown, a close coil 106 for restricting the amount of condensation of the injected steam, a draw-off 107 for the water of condensation, and a draw-o'l` 102 for the washed oil. This latter draw-off 102 leads to the storage tank 104.

The filters 110 are supplied with oil from tank 104 by pump 112 through pipe 113. The draw-off 114,f'leads to the storage tank 115; which is provided with a draw-off 1,16.

The following is a detailed description, by wayY of example and with reference to the accompanying drawings, of what is considered the best mode of making a water white oil for medicinal use with a viscosity of about two hundred seconds at 100 F.

from a binary stock which is specially compounded as aforesaid from petroleum of the Texas type and the Illinois-Kansas-Oklahoma type, respectively.

Bydistilling crude petroleum of the Texas type with in]ection of dry steam into' the oil in suitable stills (symbolized by still al of Fig. 1), and rerunning, if necessary or expedient, a distillate oil is obtained (in receiver Z) which has as a whole a viscosity of about 158 seconds at 100 F., a gravity of about 20.9 B. (about 0.928 specific avity), a ash point of about 160 F. operi cup method), and exhibiting no paraiiin wax when stirred at zero F. n

This distillate is reduced in volume in externally heated stills (symbolized by still p of Fig. 1) at gradually increasing temperatures (sa at temperatures around 550O F. to 650 and with injection of dry steam into the oil, allV as customary in reducing pressed paraffin distillate in paraiiin works; and the reduction is continued until the residual oil (to be withdrawn through pipe lr) has a viscosity of about 490 seconds at 100 F., gravity say about 20.0 B. (about 0.934 specific gravity).

By distilling crude petroleum of the Illinois-Kansas-0klahoma type without injection of aeriform Huid into the oil in suitable stills (symbolized by still 12 of Fi 2), and rerunning, if necessary or expe ient, and then chilling so obtained distillate (from receiver 21) in suitable apparatus symbolized by a chilling appliance 24 of Fig. 2? and pressing the chilled distillate in a fi ter press (symbolized by filter press` 26 of Fig. 2) there is obtained (in agitator 28) a distillate which has as a whole a' viscosity of about 8.5 seconds at 100 F., a gravity of about 26.5 B. (about 0.894 specific gravity) ,-a flash point of about 295 F. (open cup method) and exhibiting noV paraflin wax when stirred at zero F;

The pressed distillate is treated with sulfuric acid (agitator 28) and alkali (agitator 35), usin say fourteen pounds of sulfuric acid of a out 1.835 specific gravity to each fifty gallons of oil in the acid treatment; and the so treated oil (from tank 40) is then reduced in volume in externally heated stills (symbolized by still 43) at gradually increasing temperatures (say at temperatures around 550 F. to 650Q F.) and with injection of dry steam into the oil, all as customary in treating and reducing pressed paraflin distillate. in parailin works. The reduction is continued until the residual oil (to be withdrawn through pipe 45) has a viscosity of about 260 seconds at 100 F., gravity say about 23.2 B. (about 0.915 specific gravity). y

l The following table is based upon assays wherein the samples were 4distilled with injection of dry steam into the oil in order to avoid cracking, and with collection of the distillate in ten per cent. fractions in each assay (water excluded). From the observed gravities and viscosities of the so obtained fractions curves were plotted; and the tabulated figures were derived from said curves:

r d' un c 49o IlbiiiioiiS-Kliiat'si exas is a e a oma is 1 Gravms seconds at 1D0'g F. late, 260 seconds at 100 F.

B. Viscosity in seconds. Viscosity in seconds.

25. l] 125 24. 5 140 24. D 172 23. 5 212 23. 260 22. 5 90 305 22. O 120 360 2l. 5 157 43T 2l. 216 512 20. 5 300 58S 20. (l 425 G62 19. 5 600 19.0 1270 18. 5 2380 The two distillates are mixed together in such proportions that the mixture has as a whole a viscosity of about 425 seconds at 100 F., say about eighty per cent. by volume of the Texas distillate and twenty per cent. of that from Illinois-KansasOklahoma petroleum. The mixture constitutes stock to be operated upon as follows:

It is agitated (in agitator 50 of Fig. 3 by air injected through pipe 53) with say 5% of its volume of sulfuric acid of about 1.835 specific gravity; and 'the resulting acid sludge is removed by settling and drawing The treated oil is next agitated (in the same agitator 50) with fuming sulfuric acid, consisting 20% by weight of sulfuric anhydrid and 80% sulfuric monohydrate, and equal in amount to about thirty seven per cent. by volume of the oil subjected thereto. The said acid would best be applied in three doses. The acid sludge is separated by settlin and drawing off. The then remaining oil to be withdrawn through pipe 55) may equal about forty six per cent. of the original stock by volume. It would be lower in viscosity and lighter in gravity than said ori 'nal stock.

f a sample of said stock (in agitator 50) at the close of the acid treatment should be cleared and then tested with hot sulfuric acid, all as hereinabove set forth, the sample itself should be ractically unchanged in color; and the co eration of the originally colorless acid should be well within the hereinabove mentioned harmaceutical requirement of not darker t an a pale brown. The coloration of the hot acid should in fact be lighter than that ipossessed by a freshly prepared solution o one fourth of a gram of potassum iodid and one twentieth of a gram of iodin in one liter of distilled water.

The main body of stock, after treatment with the fuming sulfuric acid and separation of the acid sludge (in agitator 50), as aforesaid, is neutralized by agitation (agitator 58) with caustic soda lye, say of about 1.075 specificgravity; and it is afterward separated (in said agitator 58) from art at least of the spent alkali by settlin an drawing olf. Sufficient lye is used Vsay twenty per cent. by volume) for the oil to show alkaline to henol phthalein. "Water is absorbed from tlib lye by the oil, with a resulting increase in the volume of the latter, say of about four per cent.

The neutralized oil (from agitator 58) is distilled in suitable stills (symbolized by still 66) with injection of dry steam into the oil, until the residual material represents say about six per cent. of the charge. Most, if not all, of the sodiumy sulfonates remains in said residual material. The distillate (from receiver 7 5, excluding water) would be about eighty nine per cent. of the acid treated stock (equal to thirty nine per cent. of the original volume of the stock).

The said distillate is liable to contain a certain amount of sulfur, believed to be in elementary form and to be derived from sulfonic bodies remaining in the neutralized oil and reduced in distilling the latter. Said distillate is heated in stills (symbolized by still 78) at sufficient temperature to convert elementary sulfur in the oil into hydrogen sulfid, without largely reducing the volume of the oil, say around 400 F. to 500 F.; and dry steam is injected into the oil concurrently with the desulfurizing operation in order to raise the flash point or the iiash point and viscosity of the oil.

The desulfuratlon (in still 78) is considered complete when a sample of the oil will not tarnishv an immersed stri of polished copper in two hours at 212 The testing can be performed While the heating of the main body of the oil is continued; the injection of steam being interrupted unless the oil should be too low in viscosity when the sample was taken; so that a further increase in viscosit would be desirable. An experienced Workman should be `able, sometimes at least, to tell by the appearance of the copper strip at the close of a test whether the continued heating, after taking a sample, shall or shall not have suiiced to complete the desulfuration.. i

The injection of dry steam (still 78) is carried on until the o1l has about the flash point and viscosity desired in the'finished product, say a flash point (open cup) of 350 F. to 380 F. and a viscosity (1n the instant case) of about 200 seconds at 100 F. The injection of steam is continued, if necessary or expedient, after complete desulfuration; and the temperature would best be allowed tofall to about 300 F. before said injection is stopped.

No more than a small fraction of one per cent of the distillate needs to be removed in desulfurizing and raisin the flash point; and the viscosity of the oil is not necessarily affected thereby to a substantial extent. In the instant example, the volume of the deslilfurized oil of increased viscosity and flash point (in tank 82 of Fig. 4) would amount to about ninety seven per cent. of the distillate operated upon (about thirty eight per cent. of the original stock volume), this decrease in volume depending almost entirely upon the amount of insuiiiciently viscous material which passed over in the distillation (in still 66) of the acid treated oil. The subsequent removal of this material (in still 78) results in the described increase in viscosity.

The desulfurized oil of increased flash point and viscosity (from tank 82 of Fig. 4) is agitated (agitator 85) with suicient fuming sulfuric acid (say about 3% to 5%) to remove the still odor and also to remove the carbonizable substances at least to the extent necessary for a sample 0f the oil, after filtration by passing a volume of four hundred cubic centimeters in acid condition throu h two hundred rams of freshly calcined lorida clay (ful ers earth) in a glass tube one and a half inches in diameter, to stand the aforesaid hot acid test. With the described proportions of sulfuric acid, the coloration of the hot acid by the sample should be substantially lighter than the maX- imum permitted by the pharmaceutical requirement. The acid sludge is allowed to settle (in agitator 85) and is drawn off.

The injection of air into the oil (agitator 85) is carried on after drawing off the acid sludge, the oil being in its acid condition; and said injection is continued as long` as the escaping air sho-ws any trace of sulfur dioxid, by its odor, or by any other test which it may be thought well to use. The acid treated and subsequently blown oil (in tank 92) would amount to about ninety seven per cent. of the oil operated upon (equal to about thirty seven per cent. of the original volume of the stock).

The blown oil is filtered in its acid condition through freshly calcined Florida clay (filters 95) in the systematic manner described in my application No. 852,671, filed July 23, 1914, using` sufiicient clay to decolorize the oil to the condition of water white; thatis to say, as light colored at least as the liquid obtained by dissolving one-tenth gram of potassium chromate, K2Cr04, in one liter of distilled water and then diluting five cubic centimeters of this solution to one hundred cubic centimeters with distilled water. The filtered oil (in tank 97) would ordinarily be lighter in color than such liquid.

It should sufiice to use two or four filter beds each twelve feet deep. A bed of'this depth containing about twenty eight thousand pounds of the freshlycalcined Florida clay would be introduced as the final bed of theseries from time to time as the judgment of the operator based upon the inspection of the bloom, odor and taste of the filtrate and of the coloration of hot sulfuric acid by a sample may determine. Something between thirty and one hundred barrels of oil would ordinarily be received as filtrate before the introduction of a new filter bed.

Said filtrate (in tank 97 would represent about sixty five per cent. of the oil supplied to the filter beds (about twenty four per cent. of the original stock). lt would ordinarily at least be a finished product ready for the market, being colorless, tasteless, odorless, neutral to litmus, able `to meet the tests of the p-harmacopias for sulfur and for readily carbonizable substances, and having a viscosity of about 200 seconds at 100o F. and a gravity of about 28.7 B. (about 0.833 specific gravity).

Further refining operations are not, however, necessarily excluded; and, if deemed necessary or expedient, steam is injected into the oil (agitator 100) at about 212 F. so as to wash the oil in the hot waiter of condensation, as well as to remove volatile sulbstances, if any should be present in the o1 The washed oil, separated from the water, is filtered again (filters 110) .l

The processes described and claimed herein are in part in the nature of improvements on or modifications of processes described and claimed in my aforesaid application of July 23, 1914, No. 852,671.

I claim as my invention or discovery:

1. Stock for the manufacture therefrom of decolorized hydrocarbon oil, which stock has as a whole a viscosity above eighty seconds at 100 F. and is compounded of distillaxtes, that belong to different types of petroleum, viscosities, and whose respective hydrocarbons have equal gravities over a range of gravities corresponding with the lighter end of the more viscous distillate, mixed togather in such mannerthat between fifty per cent. and ninety five per cent. of said stock is distillate, which as a whole is heavier and more viscous than the stock as a whole,

. and whose hydrocarbons of equal gravities with hydrocarbons in the remainder of said stock are less viscous than these latter, substantially as described.

2. The improvement in the manufacture of decolorized hydrocarbon oil by means (in part at least) of an operation known to be and are as a whole of differentcapable of removing color from yiscous petroleum, which improvement consists in decolorizing by such means stock that has as a whole a viscosity above eighty seconds at 100o F. and is compounded of distillates that belong to different types of petroleum and are as a whole of different viscosities, and whose respective hydrocarbons have equal gravities over a range of gravities corresponding with the lighter end of the more viscous distillate, mixed together in such manner that between fifty per cent. and ninety five per cent. of said stock is distillate, which as a whole is heavier and more viscous than the stock as a whole, and whose hydrocarbons of equal gravities with hydrocarbons in the remainder of said stock are less viscous than these latter, substantially as described.

3. The improvement in the manufacture of decolorized hydrocarbon oil, which improvement consists in the two steps of (first) compounding stock that has as a whole a viscosity above eighty seconds at 100 F. by mixing together distillates that belong to different types of petroleum and are as a whole of different viscosities, and whose respective hydrocarbons have equal gravities over a range of gravities corresponding with the lighter end of the more viscous distillate, in such manner that between fifty per cent. and ninety-five per cent. of said stock is distillate, which as a whole is heavier and more viscous than the stock as a whole, and whose hydrocarbons of equal gravities with hydrocarbons in the remainder of said stock are less viscous than these latter, and (second) decolorizing son compounded stock by means (in part at least) of an operation known to be capable of removing color from viscous petroleum, substantially as described.

4. The improvement in the manufacture of decolorized hydrocarbon oil, by means (in part at leastg o a subjection of the stock to the action o sulfuric acid, the main part at least of which is in the form of stronger acid than `that of 1.835 specific gravity, which improvement consists in decolorizing by such means stock that has as a whole a viscosity above eighty seconds at 100 F. and is compounded of distillates that belong to different types of petroleum and are as a whole of different viscosities, and Whose respective hydrocarbons have equal gravities over a range of gravities corresponding with the llghter end of the more viscous distillate, in such manner that between fifty per cent. and ninety-five per cent. of said stock is distillate, which as a whole is heavier and more viscous than the stock as a whole, and

whose hydrocarbons of equal gravities with 5. The process of making decolorized hydrocarbon oil, which process includes the following operations in combination, namely: (first) subjecting stock, which is suitable to 6 yield finished oil with a viscosity above eighty seconds at 100 F., to the action of sulfuric acid, the main part at least of which is in the form of stronger acid than that of 1.835 specific gravity, to such extent that a 10 cleared sample of the so treated oil will not color hot sulfuric acid of 1.835 specific gravity darker than a pale shade of brown, (second) separating the acid sludge from the so treated oil, (third) subjecting the acid treated oil, after neutralization with alkaline material, to distillation with use of special agency to avoid decomposition, and (fourth) filtering the distillate through solid decolorizing material, substantially as described.

6. The process of making decolorized hy drocarbon oil,which process includes the following operations in combination, namely: (first) subjecting stock, which is suitable to yield finished oil with a viscosity above eighty seconds at 100 F.,`to the action of sulfuric acid, the main part at least of which is in the form of stronger acid than that of 1.835 specific gravity, to such extent that a 80 cleared sample of the so treated oilwill not color hot sulfuric acid of 1.835 specific gravity darker than a pale shade of brown, (second) separating the acid sludge from the so treated oil, (third) subjecting the acid treated oil, after neutralization with alkaline material, to distillation with use of special agency to avoid decomposition, (fourth) subjectin the distillate to the action of sulfurlc aci so as to form an acid sludge,

which is removed, and (fifth) filtering the acid treated oil through solid decolorizing material, substantially as described.

7. The process of making decolorized hydrocarbon oil, which process includes the following operations in combination, namely: (first) subjecting stock, whose constituent hydrocarbons have viscosities above forty seconds at 100 F., to the action of sulfuric ,acid, the main part at least of which is in 60 the form of stronger acid than that of 1.835 specificl gravity, (second) separating the acid sludge from the so treated oil (thlrd) subjecting the acid treated oil, after neutralization with alkaline material, to distillation with use of special agency to avoid decomposition, and (fourth) desulfurizing the distillate by heatmgFit at temperatures around 400 F to 500 so as to convert the elementar sulfur -therein into hydrogen sulfid wit out unduly distilling the oil,

substantially as described.

8. The process of making decolorized hydrocarbon oil, which process includes the following operatons in combination, namely:

66 (first) subjecting stock, whose constituent hydrocarbons have viscosities above forty seconds at 100 F., to the action of sulfuric acid, the main part at least of which is in the form of stronger acid than that of 1.835 specific gravity, (second) .separating the acid sludge from the so treated oil, (third) subjecting the acid treated oil, after neutralization with alkaline material, to distillation with use of special agency to avoid decomposition, (fourth) desulfurizing the distillate by heatirig it at temperatures around 400 F. to 500 so as to conve-rt the elementary sulfur therein into hydrogen sulfid Without unduly distilling the oil, and fifth) injecting aeriform fluid into the dlstillate until an increase in the fiash oint, or flash point and viscosit of the oil) has been effected, the desulfurlzation and the injection of aeriform liuid being advantageously but not nec essarily performed concurrently (for part of the time at least), substantially as'described:

9. The process of making decolorized hydrocarbon oil, which process includes the following operations in combination, namely: (first) subjecting stock, whose constituent hydrocarbons have viscosities above forty seconds at 100 F., to the action of sulfuric acid, the main part at least of which is in the form of stronger acid than that of 1.835 specific gravity, (second) separating the acid sludge from the so treated oil, (third) separating the sulfonic bodies that remain in the acid treated oil after separation of the acid sludge therefrom, (fourth) injecting aeriform Huid into the oil, from which said sulfonic bodies have been separated, until an increase in the flash point, or flash point and viscosity, ofv the oil has been effected, (fifth) subjecting the said oil to the action of sulfuric acid, so as to form an acid sludge, which is removed, and (sixth) filtering the high fiash acid treated yoil through solid decolorized material, substantially as described.

10. The process of making decolorized hydrocarbon oil, which process includes the following operations in combination, namely: (first) subjecting stock, whose constituent hydrocarbons have viscosities above forty 115 seconds at 100 F. to the action of sulfuric acid, the main part at least of which is in the form of stronger acid than that of 1.835 specific gravity, (second) se aratin the acid sludge from the so trea oil, (t vird) separatin the sulfonic bodies that remain in the acld treated oil after separation of the acid sludge therefrom, (fourth) sub'ecting oil from which said sulfonic bodies ave been separated to the action of sulfuric acid, so as to form an acid slud e, which is removed (fifth) injecting aerlform fluid into the oi, after removal of the acid sludge therefrom, on com letion of the last mentioned sulfuric aci treatment, and thereby 180 freein said oil from sulfur dioxid, and (sixth filtering the acid treated oil, so freed rom sulfur dioxid, through solid decolorizing material, substantially as described.

11. The process of making decolorized hydrocarbon oil, which process includes the following o erations in combination, namely: (first) su jecting stock, which is suitable to yield finished oil With a viscosity above eighty seconds at 100 F., to the action of su furic acid, the main part at least of which is in the form of stronger acid than that of 1.835 specific gravit to such an extent that a cleared sample o the so treated oil will not color hot sulfuric acid of 1.835 specific gravity darker than a pale shade of brown, (second) separating the acid sludge from the so treated oil, (third) subjecting the acid treated oil, after neutralization With `alkaline material, to distillation with use of special agency to avoid decomposition, and (fourth) subjecting the so obtained distillate to (Tat least) a heating around 400 F. to 500 an injection of aeriform fluid, an agitation With sulfuric acid so as to form an acid sludge which is removed, and a filtration through solid decolorizing material of the distillate after it has undergone the said heating, injection and sulfuric acid treatments, substantially as described.

12. The process of making the decolorized hydrocarbon oil, which process includes the following operations in combination,

namely: (first) subjecting stock, Whose constituent hydrocarbons have viscosities above forty seconds at 100 F., to the action of sulfuric acid, the main part at least of which is in the form of stronger acid than that of 1.835 specific gravity, (seco-nd) separating the acid sludge from the so-treated oil, (third) subjecting the acid treated oil, 5;

after neutralization with alkaline material,-

June, 1917.`

ERNEST B. COBB.

It is hereby certified that in Letters Patent No. 14,888,832, granted August 23, 1921, upon the application of Ernest B. Cobb, of Jersey City, New Jersey, for an improvement in The Manufacture of Medicinal Oils and Other Viscous Decolorized Products of Petroleum, errors appear in the printed `specification requiring correction as follows: Page 3, line 51, for the word "or read oj'; same page, liiie 57,

after the Word brown" and before the comma. insert the merk page. 4, line 1, for

treatement' read treatmentfpage 5, line 17, after the word through insert the word pipe," and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oce,

signed and sealed this 20th oe3', of october, A. D., 1921.l

[SEAL] WM. A. KINNAN,

j Acting Commissioner of Patents. 

